v1.67.2.0 feat: gpt-5.6-sol bounded-scope profile for Codex installs (#2633)

* feat: model taxonomy gains gpt-5.6-sol + per-host generation defaults

Adds 'gpt-5.6-sol' to the model taxonomy with exact-match-only resolution
(Terra/Luna/suffixed IDs deliberately fall back to generic gpt) and replaces
the hardcoded 'claude' generation default with a validated
HostConfig.defaultModel: codex renders the gpt profile when --model is
absent, every other host keeps claude. Codex ship golden regenerated
accordingly; ADDING_A_HOST documents the new field.

* feat: gpt-5.6-sol bounded-scope overlay + scope-aware resolvers

The Sol profile pins the explicit task as the lake: adjacent work is
report-only, investigation is bounded, runs terminate on one clean
verification pass, and the AskUserQuestion decision-brief format is never
trimmed. The overlay wrapper grants scope-interpretation precedence while
concrete workflow steps, gates, and skill-mandated re-verification loops
still win. Sol-specific Completeness Principle and first-run intro copy.
New SETUP_COMMAND resolver renders './setup --host <host>' for every
non-claude host so generated upgrade skills reinstall their own host.

* feat: setup reads the Codex model from config.toml

New resolve-codex-generation-model.ts reads the top-level model from
${CODEX_HOME:-~/.codex}/config.toml, validates against the model allowlist,
strips control characters from every config-derived string it surfaces,
guards against non-absolute config locations, and warns on Sol near-misses.
setup runs it on EVERY invocation (read-only TOML lookup) so a plain
./setup can never clobber a Sol user's rendered profile with the hardcoded
fallback; --model <id> overrides for one run and prints the persistence
hint. Kiro installs render the claude profile before copying (Kiro fronts
Claude-family models), rewrite the baked setup command to --host kiro, and
restore the resolved Codex profile after; the codex skills path honors
CODEX_HOME. Static pins cover the resolver wiring, fail-closed exit,
quoted argv, and the Kiro sandwich.

* feat: hermetic Codex runner hardening + Sol scope-termination E2E

The Codex E2E runner copies auth.json only (operator plugins, MCP servers,
rules, and skills no longer leak into hermetic evals), pins CODEX_HOME to
the temp dir, and supports per-run model, TOML overrides, and
--ignore-user-config. New periodic E2E installs the FULL generated
investigate skill on gpt-5.6-sol against a planted one-line bug with decoy
TODOs: the fix must land inside the boundary (untracked files counted via
git status --porcelain), decoys stay byte-identical, the regression oracle
survives unweakened, nothing gets committed, all within 30 tool calls.
The shared .agents tree is snapshotted and restored exactly in beforeAll;
fixture commits disable gpg signing. Wired into the periodic CI matrix,
paid-shard globs, eval scripts, touchfiles/E2E_TIERS
(codex-sol-scope-termination), and diff-based selection. Real-file
periodic-tier classification pins both codex E2Es out of the gate tier.
Free-tier test proves an explicit --model overrides the host default
through the real generation CLI.

* chore: bump version and changelog (v1.67.2.0)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* docs: post-ship documentation sync for v1.67.2.0

- README: Codex skills path is CODEX_HOME-aware; state that
  --model overrides detection for one run only (persist via
  the Codex config.toml model key)
- CONTRIBUTING: add the model-overlay axis to the per-host
  config table (per-host defaultModel, override precedence)
- CLAUDE.md: eval results dir is ~/.gstack/projects/<slug>/evals/
  (legacy fallback ~/.gstack-dev/evals/), matching eval-store.ts
  and the eval:* CLI headers

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* docs: post-ship documentation sync (v1.67.2.0)

Sol exact-match and near-miss warning documented in README; CODEX_HOME-aware
uninstall and troubleshooting paths; hermetic auth.json-only detail and the
build-clobber gotcha in CLAUDE.md; eval-store location corrected in
ARCHITECTURE.md; defaultModel row in the ADDING_A_HOST field reference;
resolver test count corrected in the CHANGELOG entry.

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

scripts/gen-skill-docs.ts

@@ -92,12 +92,13 @@ const HOST_ARG_VAL: HostArg = (() => {
 let HOST: Host = HOST_ARG_VAL === 'all' ? 'claude' : HOST_ARG_VAL;
 
 // ─── Model Overlay Selection ────────────────────────────────
-// --model is explicit. We do NOT auto-detect from host (host ≠ model).
-// Default is 'claude'. Missing overlay file → empty string (graceful).
+// --model is explicit. Without it, each host uses HostConfig.defaultModel.
+// Host defaults are generation fallbacks, not claims that host === model.
+// Missing overlay file → empty string (graceful).
 import { ALL_MODEL_NAMES, resolveModel, type Model } from './models';
 const MODEL_ARG = process.argv.find(a => a.startsWith('--model'));
-const MODEL_ARG_VAL: Model = (() => {
-  if (!MODEL_ARG) return 'claude';
+const MODEL_ARG_VAL: Model | null = (() => {
+  if (!MODEL_ARG) return null;
   const val = MODEL_ARG.includes('=') ? MODEL_ARG.split('=')[1] : process.argv[process.argv.indexOf(MODEL_ARG) + 1];
   const resolved = resolveModel(val);
   if (!resolved) {
@@ -106,6 +107,10 @@ const MODEL_ARG_VAL: Model = (() => {
   return resolved;
 })();
 
+function generationModelForHost(host: Host): Model {
+  return MODEL_ARG_VAL ?? getHostConfig(host).defaultModel;
+}
+
 // ─── Catalog Mode (v1.45.0.0 T4) ────────────────────────────
 // 'trim' (default): shorten frontmatter description to lead sentence and
 // move routing/voice prose into a "## When to invoke" body section.
@@ -753,7 +758,7 @@ function buildContext(
   const interactive = interactiveMatch ? interactiveMatch[1] === 'true' : undefined;
   return {
     skillName, tmplPath, benefitsFrom, host, paths: HOST_PATHS[host],
-    preambleTier, model: MODEL_ARG_VAL, interactive, explainLevel: EXPLAIN_LEVEL,
+    preambleTier, model: generationModelForHost(host), interactive, explainLevel: EXPLAIN_LEVEL,
   };
 }